Simply, the 6.5 Creedmoor offers the hunter/shooter, whether he shoots factory or handloads, factory rifle or custom, the most practical 6.5mm cartridge that fits in a true 2.8" short action rifle, IF he wants to shoot a heavy for caliber, sleek, 140+ class bullet.
The 260 Remington is a great cartridge, and when it came out in 1997, it was offered in factory ammo form as either a 125gr Nosler Partition, or 140gr Core Lokt. Rifles were either 20" Model Seven stainless or 24" Model 700 BDL SS DM. There was no PRS, there was no tactical bolt guns (Maybe a Rem 700 Police), and Remington labeled it as a deer cartridge
The Creed began life as a target cartridge, engineered to work best in 2.8" short actions with fast twist barrels and heavy for caliber bullets. Lots of rifles available. Lots of ammo. Lots of brass. Lots of people shooting it. It makes sense